Various polymeric compositions used in the formation of intraocular lenses (IOLs) are known. Formation of these polymeric compositions from various monomers of different functionality can dramatically affect the properties of the resulting IOL. Often a monomer capable of absorbing ultraviolet (UV) radiation is incorporated into the polymeric composition. Addition of the UV-absorbing monomer can change the overall composition of the polymer, and thus can dramatically affect the properties of the resulting IOL. For examples of IOL materials and methods of making, see, e.g., U.S. Pat. Nos. 7,947,796, 7,387,642, 7,067,602, 6,517,750 and 6,267,784 each of which is hereby incorporated by reference in its entirety. Additionally, see U.S. Patent Publication Nos. 2008/0221235, 2006/0276606, 2006/0199929, 2005/0131183, 2002/0058724, 2002/0058723 and 2002/0027302 each of which is hereby incorporated by reference in its entirety.
Many UV absorbing compounds contain aromatic pi-electron systems that are known to change characteristics of a final polymer, such as for example refractive index. Furthermore, increasing the concentration of UV-absorbing monomer may change the overall hydrophilicity or hydrophobicity of the polymer due to the presence of additional UV-absorbing moieties in the polymer. Therefore, addition of a substantial amount of a new component to an IOL polymer composition, may result in significant change to the properties of the compound, which already may have established commercial and/or regulatory significance to an already existing product.
Already existing IOL products that contain UV-absorbing moieties within the polymeric compound, such as for example those comprising a benzophenone moiety, may not provide adequate UV absorbing at certain wavelengths without a substantial increase in the concentration of the benzophenone moiety from currently developed compositions. The substantial increase in UV absorbing moiety, such as benzophenone, may alter the physical properties of the resulting compound and thereby require reformulation and/or recertification of a commercial compound. Therefore, a need exists for the incorporation of UV-absorbing compounds that can be incorporated into a polymeric composition suitable for IOLs in concentrations low enough as to not significantly alter the characteristics of the IOL—other than transmittance of UV—when compared to the same formulation without the new UV-absorbing compound. The new compound, for these needs, should impart UV-absorbing properties so that the formed IOL may reduce transmittance of UV rays by at least 90% at a wavelength of 370 nm.